The present invention generally relates to aircraft landing gear. More particularly, the invention relates to landing gear with integrated electric drive systems to propel an aircraft during taxiing.
A typical aircraft may taxi to and from runways with thrust force developed by its engines. A significant amount of fuel may be burned by the engines during a typical aircraft taxi profile before and after each flight. In many cases, the main engines may provide more motive force than is required to complete a successful taxi profile. In that regard, engine-thrust taxiing may be considered inefficient and may contribute to high fuel costs and ground level emissions.
Aircraft designers have sought a more efficient method for propelling an aircraft during taxiing. Electric taxi systems (ETS) have been proposed to provide higher efficiency. An ETS may be implemented by using electrical motors to provide the motive force for aircraft taxiing. While this general ETS concept holds promise for improved efficiency, there are practical application problems that need to be addressed in any successful ETS design. For example, it is desirable that an ETS should be selectively engageable with wheels of the aircraft so that the ETS does not impact normal take-off and landing procedures or aircraft performance. It is also desirable to construct an ETS with compact and lightweight components which may be retrofitted onto existing aircraft and may perform reliably even when exposed to varying environmental conditions that may be encountered by the aircraft at various airports.
As can be seen, there is a need for a selectively engageable ETS which may not interfere with normal take-off and landing procedures or aircraft performance. In that regard, it would be desirable to construct an ETS with a self-disengaging system interposed between an electric-motor drive train and an aircraft wheel. More particularly, there is a need for a self-disengaging system for such an ETS which may be compact in size, which may operate reliably under widely varying environmental conditions and which may be retrofitted onto existing aircraft with minimal structural changes to the existing aircraft.